I typically don't get these - not that there's anything actually wrong with them but I generally would prefer to pick up the pack based team sets and get pretty much all the players for the team, nit just a subset (since generally I'll get that subset in the 1st and 2nd Version sets as well as Calbee). So I wasn't planning on getting this year's Fighers set (called "Opening") but for whatever reason the seller on Yahoo! Japan Auctions that I get my Classic set from included the 27 card base set in the box with it.
It's not an unattractive set. The cards feature the players on a blue-ish background with a gold facsimile signature. Here's some example cards:
The set contains pretty much who you'd expect - Shohei Ohtani, Sho Nataka, Brandon Laird, Daikan Yoh, Kohei Arihara, Kensuke Tanaka, Shoto Ohno and Luis Mendoza to name a few. The biggest players I see missing are the two new foreign pitchers - Anthony Bass and Chris Martin. Since the set was released in March I figure most of the photos were taken either last year or at some sort of training in Japan over the winter to get the rookies in the set (Takayuki Katoh and Kenta Uehara) so they probably didn't have a chance to get pictures of Bass and Martin.
You can see all the cards at Jambalaya.
It was a nice surprise to get the set (free is always good) but I still don't have a great urge to run out and get any of these box sets. But they are nice looking. I'm sure they're even nicer (although much more expensive) when they include the autographed card.